Combustion characteristics and fire extinguishing characteristics of ultrafine dry powder fire extinguishing device

Edit:Jiangsu Yongtai Fire Engineering Co., Ltd.UpDate:2019-12-09

The particle size of the dry powder extinguishing agent is directly related to its fire extinguishing efficiency. The larger the critical particle size of the fire extinguishing component, the better the fire extinguishing effect. Therefore, preparing ultra-fine fire extinguishing powder that can be evenly dispersed and suspended in the fire space to ensure the particle activity of the fire extinguishing components and reduce the amount of fire extinguishing agent used per unit space is a very effective means to improve the fire extinguishing efficiency of dry powder fire extinguishing agent.

Combustion characteristics of superfine dry powder fire extinguishing device:

Combustion is a type of violent oxidation reaction involving oxidants, and the combustion process is a chain reaction. With the participation of high temperature and oxygen, the combustible molecules are activated to generate free radicals. The free radical energy is very high and extremely active. Once generated, it immediately triggers the next reaction and generates more free radicals. These many free radicals with high energy are once again Initiate a greater number of free radicals. In this way, depending on the free radical continuous chain reaction, the molecules of the combustible substance are gradually cracked to maintain the continuous combustion.

Fire extinguishing characteristics of ultra-fine dry powder fire extinguishing device:

Asphyxiation, cooling, and chemical inhibition of flame combustion are the concentrated expression of dry powder fire extinguishing efficiency. Among them, chemical inhibition is the basic principle of fire extinguishing and plays a major role in extinguishing fire. The fire extinguishing component in the dry powder fire extinguishing agent is an inactive substance of the combustion reaction. When it enters the flame in the combustion area, the free radicals generated by the decomposition react with the free radicals such as H and OH generated in the flame combustion reaction to capture and terminate the combustion. The free radicals produced by the reaction reduce the rate of the combustion reaction.

When the dry powder concentration in the flame is high enough, the contact area with the flame is large enough, and the rate of free radical termination is greater than the rate of combustion reaction generation, the chain combustion reaction is terminated, and the flame is extinguished.

The dry powder fire extinguishing agent is endothermic and decomposed in the combustion flame. Because each step of the decomposition reaction is an endothermic reaction, it has a good cooling effect. In addition, the decomposition of ammonium dihydrogen phosphate at a high temperature generates a glass-like thin film residual covering on the surface of the solid material to cover the surface, preventing combustion from proceeding and preventing re-ignition.